[Zealotux]

It’s explained in the article: the image is a square (even though it looks like a circle), rotating a square cannot be done in place, it’ll shift the layout as it rotates, provoking a new paint of the entire page on each animation frame.

This is how the author explains it, but it sounds suspicious to me, I’m not sure a CSS animate rotation would cause shifts in that case.

[542458]

Yeah, a CSS rotate is just a visual effect - it doesn’t change the item’s actual box size and therefore doesn’t cause page reflows. I suspect there’s something else happening here. It may be that it’s triggering a repaint of adjacent regions or the entire table.

[paradox460]

Something running on every animation frame to check if the build is complete maybe?

[ioulian]

You are right, this would not cause layout to recalculate, only repaint. And propably repaint only a section of the screen, not the whole window.